FIELD OF THE INVENTION
[0001] The invention relates to a method for determining an ophthalmic lens adapted to a
wearer based on the prescription of the wearer and at least a locomotion parameter
of the wearer.
BACKGROUND OF THE INVENTION
[0002] Usually, a person needing to wear spectacles and having thus a prescription filled
by an ophthalmologist or optometrist goes to the shop of an optician. The optician
orders a pair of optical lenses corresponding to the prescription of the wearer.
[0003] The pair of optical lenses sent to the optician are designed and manufactured according
to optical criteria determined based on the prescription of the wearer.
[0004] Recent improvements in the field of ophthalmic lenses, have allowed providing customized
optical lenses, such customization going beyond the wearer's prescription. Further
parameters than the wearer's prescription may be considered when designing and manufacturing
the pair of ophthalmic lenses.
[0005] To meet new needs or specifications of the wearer, methods of optimization of optical
lenses depending on the setting of segmentation / customization are usually used.
[0006] Usually, the prescription of the wearer is determined in a static state and the optical
design of the spectacle lenses to be provided to the wearer is determined considering
a static visual target.
[0007] However, most of the time when a wearer is using the spectacle lenses he or she is
moving relative to the visual environment.
[0008] Therefore, there is a need for a method for determining an ophthalmic lens that would
be adapted to the fact that the wearer is actually moving most of the time when using
the ophthalmic lens.
[0010] One object of the present invention is to provide a new method for determining an
ophthalmic lens as defined in the claims, and adapted to a wearer considering the
locomotion of the wearer when wearing the ophthalmic lenses.
SUMMARY OF THE INVENTION
[0011] To this end, the invention proposes a method as defined in the claims, implemented
by computer means, for determining an ophthalmic lens adapted to a wearer, the method
comprising:
- a wearer data providing step, during which wearer data comprising at least an indication
of the prescription of the wearer are provided,
- a locomotion scenario providing step during which a locomotion scenario is provided,
the locomotion scenario comprising at least an input locomotion parameter and visual
environment data indicative of a visual environment, the locomotion parameter comprising
at least movement data indicative of at least a translation movement of the head of
the wearer upon movement in a visual environment,
- an output parameter providing step during which a target value of an output parameter
is provided, the output parameter being a locomotion parameter of the wearer or an
optical parameter of the ophthalmic lens having an impact on a locomotion parameter
of the wearer,
- an ophthalmic lens determining step, during which an ophthalmic lens adapted to the
wearer is determined based at least on the wearer data so as to have the output parameter
as close as possible to the target value of the output parameter when carrying out
the locomotion scenario using the ophthalmic lens.
[0012] Advantageously, the method of the invention allows determining the ophthalmic lens
adapted to a wearer based at least on the prescription of the wearer and a locomotion
parameter of the wearer. Therefore, the ophthalmic lens determined by the method of
the invention is more adapted to the movements of the wearer.
[0013] According to further embodiments which can be considered alone or in combination:
- the input locomotion parameter is a parameter of the wearer when carrying out the
locomotion scenario using the ophthalmic lens; and/or
- the locomotion parameter is the trajectory and/or the speed and/or the direction and/or
the movements of any part of the body, for example the head, and/or the eye direction
and/or the eye movements and/or the stability and/or the yaw and/or the pitch and/or
the roll and/or the bounce and/or the sway of the wearer when carrying out the locomotion
scenario using the ophthalmic lens; and/or
- the ophthalmic lens comprises a zone of optical interest and during the ophthalmic
lens determining step the optical function of at least a first part of the zone of
optical interest is determined based at least on the output parameter and the prescription
of the wearer; and/or
- the optical function of at least a second part of the zone of optical interest is
determined without considering the locomotion parameter; and/or
- the dimensions and/or the position of the first part of the zone of optical interest
are determined based on the locomotion scenario and/or wearer personalization data
relating indicative of at least to the age and/or the morphology and/or the sensory
motor state of the wearer; and/or
- the ophthalmic lenses determining step further comprises a optical function selecting
step during which an optical function is selected in a list consisting of at least
two optical functions, the optical function being selected based at least on the wearer
data; and/or
- the wearer data further comprise a troubling output parameter and during the optical
function selecting step an optical function is selected so as to minimize the troubling
output parameter when carrying out the locomotion scenario using the ophthalmic lens;
and/or
- the locomotion parameter of the wearer is measured using a sensing device carried
by the wearer upon movement in the visual environment; and/or
- the locomotion parameter of the wearer is determined based on a statistic model of
an average wearer, for example from a database; and/or
- the ophthalmic lenses determining step further comprises a geometry determining step
during which geometrical parameter of the ophthalmic lens are determined, the geometrical
parameters being determined based at least on the wearer data; and/or
- the ophthalmic lenses determining step further comprises:
∘ a set of parameters providing step, during which a set of parameters of the ophthalmic
lens is provided, the set of parameter comprising at least an output parameter of
the wearer when carrying out a locomotion scenario using the ophthalmic lens,
∘ a set of cost functions providing step during which for each parameter of the set
of parameter a cost function is provided,
∘ during the ophthalmic lens determining step the ophthalmic lens is determined so
as to minimize the global cost function the global cost function being a weighted
sum of the cost functions; and/or
- the output parameter is the retinal flow of the wearer when carrying out the locomotion
scenario using the ophthalmic lens; and/or
- the visual environment and the ophthalmic lens are virtually simulated; and/or
- the wearer is virtually simulated.
[0014] The invention further relates to a computer program product comprising one or more
stored sequences of instructions that are accessible to a processor and which, when
executed by the processor, causes the processor to carry out the steps of the method
according to the invention.
[0015] The invention also relates to a computer-readable storage medium having a program
recorded thereon; where the program makes the computer execute the method of the invention.
[0016] The invention further relates to a device comprising a processor adapted to store
one or more sequence of instructions and to carry out at least one of the steps of
the method according to the invention.
[0017] Unless specifically stated otherwise, as apparent from the following discussions,
it is appreciated that throughout the specification discussions utilizing terms such
as "computing", "calculating", or the like, refer to the action and/or processes of
a computer or computing system, or similar electronic computing device, that manipulate
and/or transform data represented as physical, such as electronic, quantities within
the computing system's registers and/or memories into other data similarly represented
as physical quantities within the computing system's memories, registers or other
such information storage, transmission or display devices.
[0018] Embodiments of the present invention may include apparatuses for performing the operations
herein. This apparatus may be specially constructed for the desired purposes, or it
may comprise a general purpose computer or Digital Signal Processor ("DSP") selectively
activated or reconfigured by a computer program stored in the computer. Such a computer
program may be stored in a computer readable storage medium, such as, but is not limited
to, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical
disks, read-only memories (ROMs), random access memories (RAMs) electrically programmable
read-only memories (EPROMs), electrically erasable and programmable read only memories
(EEPROMs), magnetic or optical cards, or any other type of media suitable for storing
electronic instructions, and capable of being coupled to a computer system bus.
[0019] The processes and displays presented herein are not inherently related to any particular
computer or other apparatus. Various general purpose systems may be used with programs
in accordance with the teachings herein, or it may prove convenient to construct a
more specialized apparatus to perform the desired method.
[0020] The desired structure for a variety of these systems will appear from the description
below. In addition, embodiments of the present invention are not described with reference
to any particular programming language. It will be appreciated that a variety of programming
languages may be used to implement the teachings of the inventions as described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Embodiments of the invention will now be described, by way of example only, and with
reference to the following drawings in which:
- Figure 1 is a flowchart of the steps of a method according to the invention,
- Figure 2 is a flowchart of the steps of a method according to an embodiment of the
invention,
- Figure 3 illustrates an example of locomotion scenario in an embodiment of the invention,
and
- Figures 4 to 7 illustrate an example of implementation of the method of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] The invention relates to a method, for example implemented by computer means, for
determining an ophthalmic lens adapted to a wearer.
[0023] As illustrated on figure 1, the method according to the invention comprises at least:
- a wearer data providing step S1,
- a locomotion scenario providing step S2,
- an output parameter providing step S3, and
- an ophthalmic lens determining step S4.
[0024] During the wearer data providing step S1, wearer data comprising at least an indication
of the prescription of the wearer are provided.
[0025] In the sense of the invention, the prescription is a set of optical characteristics
of optical power, of astigmatism and, where relevant, of addition, determined by an
ophthalmologist in order to correct the vision defects of an individual, for example
by means of a lens positioned in front of his eye. Generally speaking, the prescription
for a progressive addition lens comprises values of optical power and of astigmatism
at the distance-vision point and, where appropriate, an addition value.
[0026] During the locomotion scenario providing step S2 a locomotion scenario is provided.
[0027] The locomotion scenario comprises at least visual environment data indicative of
a visual environment.
[0028] The visual environment data may be indicative of structure, texture of the world
and objects, light atmosphere, spatial frequencies, presence of objects, people, etc...
[0029] The visual environment may be a real word environment or a virtually simulated environment.
[0030] When the visual environment is a real word environment, the visual environment data
may be measured by sensors either worn by the wearer or placed in the environment.
[0031] For example, according to an embodiment of the invention, the locomotion parameter
of the wearer is measured using a sensing device carried by the wearer upon movement
in the visual environment.
[0032] When the visual environment is a virtual simulated visual environment, the visual
environment data may be at least part of the data defining the virtual simulated visual
environment.
[0033] The locomotion scenario further comprises at least an input locomotion parameter
comprising at least movement data indicative of at least a translation movement not
null, of the head of the wearer upon movement in a visual environment.
[0034] The locomotion parameters may comprise wearer's movement features such as trajectory,
speed, directions and movements of any part of the body, for example of the head,
such as rotations and translations of head, directions and eye movements (gazing down,
eccentricity ...), how to cross an obstacle for example raising the foot, the yaw,
pitch, roll, bounce and sway, segmental and oculomotor coordination (Vestibulo-Ocular
Reflex, anchoring index), the stability of the body during walking ...
[0035] The locomotion scenario may further comprise indication concerning the type of movement
of the wearer in the visual environment for example driving, walking, bicycling, running,
going up or down the stairs.
[0036] Preferably, the input locomotion parameter is a locomotion parameter of the wearer
when carrying out the locomotion scenario using an ophthalmic lens.
[0037] During the output parameter providing step S3 a target value of an output parameter
is provided. The output parameter may be a locomotion parameter of the wearer or an
optical parameter of the ophthalmic lens having an impact on a locomotion parameter
of the wearer.
[0038] According to an embodiment of the invention, the locomotion parameter may be selected
in the list consisting of the trajectory, the speed, the direction of the head or
any other parts of the body of the wearer, head movements, the eye gazing direction,
the eye movements, the stability, the yaw, the pitch, the roll, the bounce, the sway
of the wearer when carrying out the locomotion scenario using the ophthalmic lens.
[0039] Locomotion parameter may be defined as any parameter characterizing the movement
of the wearer or perceptual parameter related to a locomotion task such as the perceived
speed of movement of objects, the optical flow, the perception an obstacle located
on the ground, the perception of vertical, horizontal, perception of the slopes, the
sensation of pitching, depth perception, perception of absolute or relative objects
distances ...
[0040] Optical parameter may be defined as a parameter that may be calculated by ray tracing
through the ophthalmic lens, such as power profile of the meridian, widths of iso
power or astigmatism lines fields, power or astigmatism gradients, wavefront, optical
flow, retinal flow, deviation maps etc....
[0041] Optical parameter may be defined within the framework of the invention as long as
it has an impact on sensorimotor behavior or perception of the wearer when moving.
Defining at least one optical parameter requires at least the definition of a locomotion
scenario. The various locomotion scenario parameters may influence the selection of
at least one optical parameter.
[0042] The optical flow can be considered both as a locomotion parameter, it characterizes
the direction and speed of movement of the wearer in the case, for example, recording
the streams over a scene camera and an optical parameter, in this case it is the optical
flow calculated by ray tracing through the ophthalmic lens.
[0043] The wearer perceives the features of his own movement via visual information such
as optic flow. The optical flow is characterized by optical changes produced by the
relative movement of the wearer's head in the environment. Retinal flow corresponds
to a projection of optical flow in retinal coordinates on the receiving surface. It
is affected by the viewing direction and rotation of the eye in the orbit. The retinal
flow is usually represented by a vector field. Each vector of the field corresponds
to a speed and a direction of movement of an element of the environment. The combination
of body movements, eyes and depth of objects in the visual environment then determine
the structure of the optical flow on the retina (Callow and Lappe (2007) Local statistics
of retinal optic flow for self-motion through natural sceneries).
[0044] Retinal flow induced by a moving wearer depends on the speed and direction of movement
of the head of the wearer, the rotation of his eyes and the composition of the environment
(structure, object distance ...). In the case of a pure translation movement of a
moving subject on a straight path forward and looking in the direction of its movement,
retinal flow matching is a purely radial expansion flow. Mostly the retinal flow combines
components in translation and rotation. When the wearer is wearing an ophthalmic lens
the retinal flow also depends on the features of the ophthalmic lens, in particular
the optical function of the ophthalmic lens.
[0045] The choice of locomotion and / or optical criteria may be dictated by wearer parameters
such as age, activities (schedule activities for example), ametropia etc ...
[0046] For example, the locomotion scenario may be the displacement of the body. The visual
environment is the ground texture in front of the wearer. The displacement of the
body is maintained stable when visual cues are available and reliable two steps ahead.
The visibility window of the ground two steps ahead projected on the lenses defined
the dimensions and location of a first part of the zone of optical interest. Inside
this first part of the zone of optical interest, an output parameter is defined as
the depth cues. A target value of this output parameter is the depth cues values computed
with a reference lens. The optimization will consist to minimize the deviation between
the target value and the depth cues values computed with the ophthalmic lens while
determining it.
[0047] According to an embodiment of the invention, the method of the invention may be used
to determine the most appropriate optical design for a progressive ophthalmic lens.
In particular, the optical design that provides a retinal flow as close as possible
to the retinal flow of a single vision plano ophthalmic lens.
[0048] As illustrated on figure 3, in such example, the locomotion scenario is the wearer
walking without moving his head and gazing at a point on the ground. The input locomotion
parameters in this example comprise the trajectory, the oculomotor direction, the
visual environment such as the ground and wall.
[0049] Specifically, the movement is translational forward on a ground consisting of a grid
according to an axis perpendicular to a vertical grid. In the initial position the
wearer is 5 m from the vertical grid and the center of rotation of the wearers eyes
are 1m70 from the ground. The wearer looks at a point on the ground.
[0050] The output locomotion parameter is the retinal flow of the wearer wearing ophthalmic
lenses. The retinal flow is calculated between the initial position of the wearer
and a final position located 25 cm away. The target value is the retinal flow of the
wearer when wearing single vision plano ophthalmic lens.
[0051] In this example, the inventors have observed that the most relevant is to focus on
the peripheral part of the retina flow, i.e. in the temporal and nasal areas.
[0052] The first progressive design EI1 corresponds to an ophthalmic lens with an addition
of 2.5 D, a far vision prescription of 0D and adapted for a head/eye movement coefficient
of 0. Figures 4a to 4c show features of the front surface of such an ophthalmic lens
having the first progressive design E1 and a refractive index of 1.665.
[0053] Figure 4a shows mean sphere curve surrounded by minimum and maximum sphere curves,
along the meridian. The x-axes are graduated in diopters, and the y-axes give the
height, in mm, on the lens.
[0054] Figure 4b shows lines of equal mean sphere, i.e. lines formed by points for which
the mean sphere has an identical value. The x-axis and y-axis give the coordinates
in mm.
[0055] Figure 4c shows, using the same axes as for figure 4b, lines of equal cylinder.
[0056] The second progressive design EI2 corresponds to an ophthalmic lens with an addition
of 2.5 D, a far vision prescription of OD and adapted for a head/eye movement coefficient
of 1. Figures 5a to 5c show features of the front surface of such an ophthalmic lens
having the second progressive design E3 and a refractive index of 1.665.
[0057] Figure 5a shows mean sphere curve surrounded by minimum and maximum sphere curves,
along the meridian. The x-axes are graduated in diopters, and the y-axes give the
height, in mm, on the lens.
[0058] Figure 5b shows lines of equal mean sphere, i.e. lines formed by points for which
the mean sphere has an identical value. The x-axis and y-axis give the coordinates
in mm.
[0059] Figure 5c shows, using the same axes as for figure 5b, lines of equal cylinder.
[0060] Figure 6a illustrates the comparison of the retinal flow with the single vision design,
represented by the arrows starting with a circle, and the retinal flow with the first
progressive design EI1 represented by the arrows starting with a circle.
[0061] Figures 6b and 6c represent focus respectively on the nasal and temporal areas of
figure 6a.
[0062] Figure 7a illustrates the comparison of the retinal flow with the single vision design,
represented by the arrows starting with a circle, and the retinal flow with the second
progressive design EI2 represented by the arrows starting with a square.
[0063] Figures 7b and 7c represent focus respectively on the nasal and temporal areas of
figure 7a.
[0064] On figures 6a and 6b the point of fixation is represented by a star.
[0065] The single arrows represent the differences between the retinal flow with the single
vision design and the progressive designs. The differences of retinal flow, single
arrows, between the single vision and the two progressive designs are measured more
specifically in the two areas of interest, i.e. temporal and nasal areas, on flow
charts expressed in the retinal reference and projected onto a sphere of 2 meters
radius centered on the cyclopean eye of the wearer.
[0066] For each progressive design, resultant vectors, represented as a solid arrows on
figures 6b, 6c, 7b and 7c corresponding to the difference between the average of progressive
design optic flow and the average of single vision optic flow are determined for two
areas (temporal and nasal) of the zone of optical interest.
[0067] For these two areas (temporal and nasal) of the optical zone of interest, the angle
and amplitude ratio between the resultant and the target value single vision optic
flow, represented as a dotted arrows on figures 6b, 6c, 7b and 7c are calculated.
[0068] Table 1 summarizes the average values obtained.
Table 1
|
EI1-ER |
EI2-ER |
|
Temporal |
Nasal |
Temporal |
Nasal |
Angle |
30.5° |
30° |
36.5° |
30.1° |
Amplitude ratio |
11.80% |
15.90% |
13.60% |
17.50% |
[0069] As illustrated in Table 1, the first progressive design E1 is the one having the
smallest difference with the single vision ophthalmic lens for the retinal flow in
peripheral vision and in the specific locomotion scenario. The wearer will be preferably
proposed a lens having the first progressive design E1 instead of the second progressive
design E2.
[0070] According to a further example of the invention, in the context of a sport, such
as tennis, the locomotion parameter may relate to the movements of the body and/or
head and/or eye of the wearer upon striking a ball, or when following the ball. The
locomotion parameter may be related to the speed of the body or the head of the wearer
to seek an ophthalmic lens that optimizes the speed of the wearer.
[0071] During the ophthalmic lens determining step an ophthalmic lens adapted to the wearer
is determined. The ophthalmic lens is determined based at least on the wearer data
and so as to have the output parameter as close as possible to the target value of
the output parameter when carrying out the locomotion scenario using the ophthalmic
lens.
[0072] Typically, the optical function and/or geometry of the ophthalmic lens is determined
either by selection or by optimization.
[0073] In the sense of the invention, an optical function corresponds to a function providing
for each gaze direction the effect of an ophthalmic lens on the light ray passing
through the optical lens.
[0074] The optical function may comprise dioptric function, light absorption, polarizing
capability, reinforcement of contrast capacity, etc...
[0075] The dioptric function corresponds to the optical lens power (mean power, astigmatism,
the prismatic deviation, etc...) as a function of the gaze direction.
[0076] The wording "optical design" is a widely used wording known from the man skilled
in the art in ophthalmic domain to designate the set of parameters allowing defining
a dioptric function of an ophthalmic lens; each ophthalmic lens designer has its own
designs, particularly for progressive ophthalmic lenses. As for an example, a progressive
ophthalmic lens "design" results of an optimization of a progressive surface so as
to restore a presbyope's ability to see clearly at all distances but also to optimally
respect all physiological visual functions such as foveal vision, extra-foveal vision,
binocular vision and to minimize unwanted astigmatisms. For example, a progressive
lens design comprises:
- a power profile along the main gaze directions (meridian line) used by the lens wearer
during day life activities,
- distributions of powers (mean power, astigmatism,...) on the sides of the lens, that
is to say away from the main gaze directions.
[0077] According to an embodiment of the invention, an ophthalmic lens design that is adapted
to a specific locomotion parameter.
[0078] According to an embodiment of the invention, the ophthalmic lens comprises a zone
of optical interest and during the ophthalmic lens determining step the optical function
of at least a first part of the zone of optical interest is determined based at least
on the output parameter and the prescription of the wearer. For example, the optical
function of at least a second part of the zone of optical interest is determined without
considering the locomotion parameter.
[0079] For example the first part of the zone of optical interest may correspond to the
visibility window of the ground two steps ahead projected on the lens.
[0080] The position and/or dimension of the first part and the second parts of the optical
lens may be interdependent or independent.
[0081] In other words, the whole surface of the ophthalmic lens does not have to be considered
when determining the optical design adapted to a locomotion parameter of the wearer.
[0082] The dimensions and/or the position of the first part of the zone of optical interest
may be determined based on the locomotion scenario and/or wearer personalization data
relating indicative of at least to the age and/or the morphology and/or the sensory
motor state of the wearer.
[0083] As indicated previously, the ophthalmic lenses determining step S4 may comprises
an optical function selecting step during which an optical function is selected in
a list consisting of at least two optical functions, the optical function being selected
based at least on the wearer data and the output parameter.
[0084] The optical function selecting step may be implemented by computer means or at least
assisted by computer means for example, via a database or lookup table.
[0085] The optical function selecting step may also consists in having the wearer carry
out the locomotion scenario using ophthalmic lenses having the different optical function
of the list and measuring the output parameter to as to select the optical functions
providing the output parameter as close as possible to the target value.
[0086] In the sense of the invention, the target value may correspond to:
- maximizing a locomotion parameter, for example maximizing movement speed,
- minimizing a locomotion parameter, for example the difference between the retinal
flow and a reference retinal flow.
- reaching a threshold value, for example minimum safety distance between the foot of
the wearer and the edge of the sidewalk,
- a defined value, for example having a target retinal flow of a single-focus lens of
the same power.
[0087] The optical function determining step may be implemented using an optimization process.
[0088] For example as illustrated on figure 2, the ophthalmic lenses determining step of
the method of the invention may further comprises:
- a set of parameters providing step S42, and
- a set of cost functions providing step S44.
[0089] During the set of parameters providing step S42 a set of parameters for optimizing
the ophthalmic lens is provided. The set of parameter comprise at least an output
parameter of the wearer when carrying out a locomotion scenario using the ophthalmic
lens.
[0090] For each parameter of the set of parameter a cost function is provided during the
set of cost functions providing step S44.
[0091] The ophthalmic lens is determined so as to minimize the global cost function, the
global cost function being a weighted sum of the cost functions.
[0092] For example according to an embodiment of the invention, the first parameter may
be the difference between the retinal flow with the ophthalmic lens and the retina
flow of an ophthalmic lens of reference, such as a single vision ophthalmic lens.
The second cost function may be the sum of the square difference over the first zone
of optical interest of the lens for which we want the retinal flow to have the retina
flow of the lens of reference.
[0093] A second parameter may be the difference between the prescription of the wearer and
the power of the ophthalmic lens. The second cost function associated with this second
parameter may be the sum of the square difference over a second zone of optical interest
of the lens for which the prescription of the wearer has to be obtained.
[0094] The global cost function is the sum the first and second cost function and is minimized
so that the above mentioned criteria are minimized.
[0095] According to an embodiment of the invention, the wearer data further comprise a troubling
output parameter.
[0096] During the optical function determining step an optical function is selected so as
to minimize the troubling output parameter when carrying out the locomotion scenario
using the ophthalmic lens.
[0097] For example, a troubling output parameter may be related to "magnification", in particular
in the lower part of the ophthalmic lens used by the wearer in locomotion situation.
The troubling output parameter may relate to the maximum magnification in the lower
part of the ophthalmic lens from which the stability of the wearer is degraded when
walking.
[0098] An example of implementation of the method of the invention is provided.
[0099] When walking, the importance of the lower visual field was shown to maintain an efficient
operation and to anticipate the obstacles on the ground. This anticipation visibility
window of visual information is to be preserved. The deformations of the environment
observed in this visibility window with a progressive lens are troublesome.
[0100] There is therefore a need to determine an ophthalmic lens limiting such troublesome.
The method of the invention may be used to determine an ophthalmic lens that eliminates
the problems of distortion and blurring associated with the near vision area while
the wearer is moving.
[0101] A modification of the optical design may be combined with a calculation of power
distribution in the lens adapted to a specific environment or a specific locomotion
activity, but also a management / change of optical aberrations, an optical function
(power, astigmatism), aesthetic criteria, linked to distortion, etc ... This can be
for example:
- by using a cost function integrating these different types of criteria and assessing
the sum of the differences (squared) between the target values and the values obtained
for the different criteria and by associating with each term a coefficient representing
its importance in computing the cost function, and/or
- by setting tolerances around a given optical function, defining a range of optical
functions in which a solution amending criterion flow and / or the power profile may
be selected.
[0102] As indicated previously, the method of the invention may be implemented having the
wearer carry out the locomotion scenario in the real word using different ophthalmic
lenses with different optical functions.
[0103] However, the method of the invention may further be implemented using a virtual locomotion
scenario and having virtual ophthalmic lenses provided to the wearer.
[0104] The invention may also be implemented on a virtual wearer having the main features
of the real wearer to determine the most appropriate ophthalmic lens for the wearer.
[0105] Furthermore, the method of the invention may be used to determine an optical design
of an ophthalmic lens to be manufactured or an optical design to be applied be sent
to an optical lens controller controlling a programmable lens.
[0106] An example a programmable lens device whose optical function can be modified is disclosed
in
WO2015014910.
[0107] Typically, a programmable ophthalmic lens comprises a transparent set of electroactive
cells juxtaposed parallel to a surface of the lens. The set of cells is suitable for
providing an optical phase-shift distribution function with a substantially constant
value within each cell.
[0108] Preferably, each cell is filled with an active electro-material such that the refraction
index can vary in each pixel independently from each other under the action of an
electric field induced by individual electrodes.
[0109] The device can be disposed on a face of the transparent set of electroactive cells
facing the eye.
[0110] Of course, the programmable lens device comprises a device adapted to provide the
adapted electric field.
[0111] It is well-known of the man skilled in the art methods to manufacture pixelated ophthalmic
lenses having unspecified surfaces.
[0112] The method of the invention may allow adapting the optical function of a programmable
optical lens to a locomotion parameter of the user. For example, upon detection or
input from the wearer that said wearer is walking the optical function may be adapted
based on a locomotion parameter.
[0113] The invention has been described above with the aid of embodiments without limitation
of the general inventive concept.
[0114] Many further modifications and variations will suggest themselves to those skilled
in the art upon making reference to the foregoing illustrative embodiments, which
are given by way of example only and which are not intended to limit the scope of
the invention, that being determined solely by the appended claims.
[0115] In the claims, the word "comprising" does not exclude other elements or steps, and
the indefinite article "a" or "an" does not exclude a plurality. The mere fact that
different features are recited in mutually different dependent claims does not indicate
that a combination of these features cannot be advantageously used. Any reference
signs in the claims should not be construed as limiting the scope of the invention.
1. A method implemented by computer means for determining an ophthalmic lens adapted
to a wearer, the method comprising:
- a wearer data providing step, during which wearer data comprising at least an indication
of the prescription of the wearer are provided,
- a locomotion scenario providing step during which a locomotion scenario is provided,
the locomotion scenario comprising at least an input locomotion parameter and visual
environment data indicative of a visual environment, the locomotion parameter comprising
at least movement data indicative of at least a translation movements of the head
of the wearer upon movement in a visual environment,
- an output parameter providing step during which a target value of an output parameter
is provided, the output parameter being a locomotion parameter of the wearer or an
optical parameter of the ophthalmic lens having an impact on a locomotion parameter
of the wearer,
- an ophthalmic lens determining step, during which an ophthalmic lens adapted to
the wearer is determined based at least on the wearer data so as to have the output
parameter as close as possible to the target value of the output parameter when carrying
out the locomotion scenario using the ophthalmic lens,
wherein the output parameter is the retinal flow of the wearer when carrying out the
locomotion scenario using the ophthalmic lens.
2. The method according to the preceding claim, wherein the input locomotion parameter
is a parameter of the wearer when carrying out the locomotion scenario using the ophthalmic
lens.
3. The method according to the preceding claim, wherein the locomotion parameter is the
trajectory and/or the speed and/or the direction and/or the movements of any part
of the body, for example the head, and/or the eye direction and/or the eye movements
and/or the stability and/or the yaw and/or the pitch and/or the roll and/or the bounce
and/or the sway of the wearer when carrying out the locomotion scenario using the
ophthalmic lens.
4. The method according to any of the preceding claims, wherein the ophthalmic lens comprises
a zone of optical interest and during the ophthalmic lens determining step the optical
function of at least a first part of the zone of optical interest is determined based
at least on the output parameter and the prescription of the wearer.
5. The method according to claim 4, wherein the dimensions and/or the position of the
first part of the zone of optical interest are determined based on the locomotion
scenario and/or wearer personalization data relating indicative of at least to the
age and/or the morphology and/or the sensory motor state of the wearer.
6. The method according to any of the preceding claims, wherein the ophthalmic lenses
determining step further comprises a optical function selecting step during which
an optical function is selected in a list consisting of at least two optical function,
the optical function being selected based at least on the wearer data.
7. The method according to any of the preceding claims, wherein the wearer data further
comprise a troubling output parameter and during the optical function determining
step an optical function is selected so as to minimize the troubling output parameter
when carrying out the locomotion scenario using the ophthalmic lens.
8. The method according to any of the preceding claims, wherein the locomotion parameter
of the wearer is measured using a sensing device carried by the wearer upon movement
in the visual environment.
9. The method according to any of the preceding claims, wherein the ophthalmic lenses
determining step further comprises a geometry determining step during which geometrical
parameter of the ophthalmic lens are determined, the geometrical parameters being
determined based at least on the wearer data.
10. The method according to any of the preceding claims, wherein the ophthalmic lenses
determining step further comprises:
- a set of parameters providing step, during which a set of parameters of the ophthalmic
lens is provided, the set of parameter comprising at least an output parameter of
the wearer when carrying out a locomotion scenario using the ophthalmic lens,
- a set of cost functions providing step during which for each parameter of the set
of parameter a cost function is provided,
during the ophthalmic lens determining step the ophthalmic lens is determined so as
to minimize the global cost function the global cost function being a weighted sum
of the cost functions.
11. The method according to any of the preceding claims, wherein the visual environment
and the ophthalmic lens are virtually simulated.
12. The method according to the preceding claim, wherein the wearer is virtually simulated.
13. A computer program product comprising one or more stored sequences of instructions
that are accessible to a processor and which, when executed by the processor, causes
the processor to carry out all the steps of the method according to any of claims
1 to 12.
14. A computer readable medium carrying the sequences of instructions of the computer
program product of claim 13.
1. Durch Computermittel implementiertes Verfahren zur Bestimmung einer an einen Träger
angepassten ophthalmischen Linse, wobei das Verfahren umfasst:
- einen Schritt zum Bereitstellen von Trägerdaten, wobei die Trägerdaten mindestens
eine Angabe der Verschreibung des Trägers bereitstellen,
- einen Schritt zum Bereitstellen eines Fortbewegungsszenarios, bei dem ein Fortbewegungsszenario
bereitgestellt wird, wobei das Fortbewegungsszenario mindestens einen Eingangs-Fortbewegungsparameter
und visuelle Umgebungsdaten umfasst, die eine visuelle Umgebung anzeigen, wobei der
Fortbewegungsparameter mindestens Bewegungsdaten umfasst, die mindestens eine Translationsbewegung
des Kopfes des Trägers bei Bewegung in einer visuellen Umgebung anzeigen,
- einen Schritt zum Bereitstellen eines Ausgangsparameters, bei dem ein Sollwert eines
Ausgangsparameters bereitgestellt wird, wobei der Ausgangsparameter ein Fortbewegungsparameter
des Trägers oder ein optischer Parameter der ophthalmischen Linse ist, der einen Einfluss
auf einen Fortbewegungsparameter des Trägers hat,
- einen Schritt zum Bestimmen einer ophthalmischen Linse, bei dem eine an den Träger
angepasste ophthalmische Linse mindestens basierend auf den Daten des Trägers bestimmt
wird, sodass der Ausgangsparameter beim Durchführen des Fortbewegungsszenarios unter
Verwendung der ophthalmischen Linse so nahe wie möglich am Sollwert des Ausgangsparameters
liegt,
wobei der Ausgangsparameter beim Durchführen des Fortbewegungsszenarios unter Verwendung
der ophthalmischen Linse der Netzhautfluss des Trägers ist.
2. Verfahren nach dem vorhergehenden Anspruch, wobei der Eingangs-Fortbewegungsparameter
beim Durchführen des Fortbewegungsszenarios unter Verwendung der ophthalmischen Linse
ein Parameter des Trägers ist.
3. Verfahren nach dem vorhergehenden Anspruch, wobei der Fortbewegungsparameter die Trajektorie
und/oder die Geschwindigkeit und/oder die Richtung und/oder die Bewegungen eines Körperteils,
zum Beispiel des Kopfes, und/oder die Augenrichtung und/oder die Augenbewegungen und/oder
die Stabilität und/oder das Gieren und/oder das Stampfen und/oder das Rollen und/oder
das Hüpfen und/oder das Schwanken des Trägers beim Durchführen des Fortbewegungsszenarios
unter Verwendung der ophthalmischen Linse ist.
4. Verfahren nach einem der vorhergehenden Ansprüche, wobei die ophthalmische Linse eine
optisch interessierende Zone umfasst und beim Schritt zum Bestimmen der ophthalmischen
Linse die optische Funktion mindestens eines ersten Teils der optisch interessierenden
Zone basierend auf mindestens dem Ausgangsparameter und der Verschreibung des Trägers
bestimmt wird.
5. Verfahren nach Anspruch 4, wobei die Abmessungen und/oder die Position des ersten
Teils der optisch interessierenden Zone basierend auf dem Fortbewegungsszenario und/oder
den Personalisierungsdaten des Trägers bestimmt werden, die sich mindestens auf das
Alter und/oder die Morphologie und/oder den sensomotorischen Zustand des Trägers beziehen
anzeigen.
6. Verfahren nach einem der vorhergehenden Ansprüche, wobei der Schritt zum Bestimmen
von ophthalmischen Linsen ferner einen Schritt zum Auswählen einer optischen Funktion
umfasst, bei dem eine optische Funktion in einer Liste ausgewählt wird, die aus mindestens
zwei optischen Funktionen besteht, wobei die optische Funktion mindestens basierend
auf den Daten des Trägers ausgewählt wird.
7. Verfahren nach einem der vorhergehenden Ansprüche, wobei die Daten des Trägers ferner
einen störenden Ausgangsparameter umfassen und beim Schritt zum Bestimmen der optischen
Funktion eine optische Funktion so ausgewählt wird, dass der störende Ausgangsparameter
beim Durchführen des Fortbewegungsszenarios unter Verwendung der ophthalmischen Linse
minimiert wird.
8. Verfahren nach einem der vorhergehenden Ansprüche, wobei der Fortbewegungsparameter
des Trägers unter Verwendung einer durch den Träger bei Bewegung in der visuellen
Umgebung getragenen Sensorvorrichtung gemessen wird.
9. Verfahren nach einem der vorhergehenden Ansprüche, wobei der Schritt zum Bestimmen
von ophthalmischen Linsen ferner einen Schritt zum Bestimmen der Geometrie umfasst,
bei dem die geometrischen Parameter der ophthalmischen Linse bestimmt werden, wobei
die geometrischen Parameter mindestens basierend auf den Daten des Trägers bestimmt
werden.
10. Verfahren nach einem der vorhergehenden Ansprüche, wobei der Schritt zum Bestimmen
der ophthalmischen Linsen ferner umfasst:
- einen Schritt zum Bereitstellen eines Satzes von Parametern, bei dem ein Satz von
Parametern der ophthalmischen Linse bereitgestellt wird, wobei der Satz von Parametern
beim Durchführen eines Fortbewegungsszenarios unter Verwendung der ophthalmischen
Linse mindestens einen Ausgangsparameter des Trägers umfasst,
- einen Schritt zum Bereitstellen von Kostenfunktionen, bei dem für jeden Parameter
des Parametersatzes eine Kostenfunktion bereitgestellt wird,
wobei beim Schritt zum Bestimmen der ophthalmischen Linse die ophthalmische Linse
so bestimmt wird, dass die globale Kostenfunktion minimiert wird, wobei die globale
Kostenfunktion eine gewichtete Summe der Kostenfunktionen ist.
11. Verfahren nach einem der vorhergehenden Ansprüche, wobei die visuelle Umgebung und
die ophthalmische Linse virtuell simuliert werden.
12. Verfahren nach dem vorhergehenden Anspruch, wobei der Träger virtuell simuliert wird.
13. Computerprogrammprodukt umfassend eine oder mehrere gespeicherte Anweisungssequenzen,
die für einen Prozessor zugänglich sind und die beim Ausführen durch den Prozessor
diesen veranlassen, alle Schritte des Verfahrens gemäß einem der Ansprüche 1 bis 12
auszuführen.
14. Computerlesbares Medium, der die Anweisungssequenzen des Computerprogrammprodukts
nach Anspruch 13 enthält.
1. Procédé mis en œuvre par des moyens informatiques pour déterminer un verre ophtalmique
adapté à un porteur, le procédé comprenant :
- une étape d'obtention de données de porteur, pendant laquelle des données de porteur
comprenant au moins une indication de la prescription du porteur sont obtenues,
- une étape d'obtention de scénario de locomotion pendant laquelle un scénario de
locomotion est obtenu, le scénario de locomotion comprenant au moins un paramètre
de locomotion d'entrée et des données d'environnement visuel représentatives d'un
environnement visuel, le paramètre de locomotion comprenant au moins des données de
mouvement représentatives d'au moins un mouvement de translation de la tête du porteur
lors d'un mouvement dans un environnement visuel,
- une étape d'obtention de paramètre de sortie pendant laquelle une valeur cible d'un
paramètre de sortie est obtenue, le paramètre de sortie étant un paramètre de locomotion
du porteur ou un paramètre optique du verre ophtalmique ayant un impact sur un paramètre
de locomotion du porteur,
- une étape de détermination de verre ophtalmique, pendant laquelle un verre ophtalmique
adapté au porteur est déterminé au moins en fonction des données de porteur de manière
à avoir le paramètre de sortie aussi proche que possible de la valeur cible du paramètre
de sortie lors de l'exécution du scénario de locomotion au moyen du verre ophtalmique,
dans lequel le paramètre de sortie est le flux rétinien du porteur lors de l'exécution
du scénario de locomotion au moyen du verre ophtalmique.
2. Procédé selon la revendication précédente, dans lequel le paramètre de locomotion
d'entrée est un paramètre du porteur lors de l'exécution du scénario de locomotion
au moyen du verre ophtalmique.
3. Procédé selon la revendication précédente, dans lequel le paramètre de locomotion
est la trajectoire et/ou la vitesse et/ou la direction et/ou les mouvements de n'importe
quelle partie du corps, par exemple la tête, et/ou la direction des yeux et/ou les
mouvements des yeux et/ou la stabilité et/ou le lacet et/ou le tangage et/ou le roulis
et/ou le rebond et/ou le balancement du porteur lors de l'exécution du scénario de
locomotion au moyen du verre ophtalmique.
4. Procédé selon l'une quelconque des revendications précédentes, dans lequel le verre
ophtalmique comprend une zone d'intérêt optique, et pendant l'étape de détermination
de verre ophtalmique, la fonction optique d'au moins une première partie de la zone
d'intérêt optique est déterminée au moins en fonction du paramètre de sortie et de
la prescription du porteur.
5. Procédé selon la revendication 4, dans lequel les dimensions et/ou la position de
la première partie de la zone d'intérêt optique sont déterminées en fonction du scénario
de locomotion et/ou de données de personnalisation de porteur concernant représentatives
au moins de l'âge et/ou de la morphologie et/ou de l'état sensori-moteur du porteur.
6. Procédé selon l'une quelconque des revendications précédentes, dans lequel l'étape
de détermination de verres ophtalmiques comprend en outre une étape de sélection de
fonction optique pendant laquelle une fonction optique est sélectionnée dans une liste
constituée par au moins deux fonctions optiques, la fonction optique étant sélectionnée
au moins en fonction des données de porteur.
7. Procédé selon l'une quelconque des revendications précédentes, dans lequel les données
de porteur comprennent en outre un paramètre de sortie perturbant, et pendant l'étape
de détermination de fonction optique, une fonction optique est sélectionnée de manière
à minimiser le paramètre de sortie perturbant lors de l'exécution du scénario de locomotion
au moyen du verre ophtalmique.
8. Procédé selon l'une quelconque des revendications précédentes, dans lequel le paramètre
de locomotion du porteur est mesuré au moyen d'un dispositif de détection porté par
le porteur lors d'un mouvement dans l'environnement visuel.
9. Procédé selon l'une quelconque des revendications précédentes, dans lequel l'étape
de détermination de verres ophtalmiques comprend en outre une étape de détermination
de géométrie pendant laquelle des paramètres géométriques du verre ophtalmique sont
déterminés, les paramètres géométriques étant déterminés au moins en fonction des
données de porteur.
10. Procédé selon l'une quelconque des revendications précédentes, dans lequel l'étape
de détermination de verres ophtalmiques comprend en outre :
- une étape d'obtention d'un ensemble de paramètres, pendant laquelle un ensemble
de paramètres du verre ophtalmique est obtenu, l'ensemble de paramètres comprenant
au moins un paramètre de sortie du porteur lors de l'exécution du scénario de locomotion
au moyen du verre ophtalmique,
- une étape d'obtention d'un ensemble de fonctions de coût pendant laquelle, pour
chaque paramètre de l'ensemble de paramètres, une fonction de coût est obtenue,
dans lequel, pendant l'étape de détermination de verre ophtalmique, le verre ophtalmique
est déterminé de manière à minimiser la fonction de coût globale, la fonction de coût
globale étant une somme pondérée des fonctions de coût.
11. Procédé selon l'une quelconque des revendications précédentes, dans lequel l'environnement
visuel et le verre ophtalmique sont simulés virtuellement.
12. Procédé selon la revendication précédente, dans lequel le porteur est simulé virtuellement.
13. Produit-programme informatique comprenant une ou plusieurs séquences d'instructions
stockées qui sont accessibles à un processeur et qui, lorsqu'elles sont exécutées
par le processeur, conduisent le processeur à réaliser toutes les étapes du procédé
selon l'une quelconque des revendications 1 à 12.
14. Support lisible par ordinateur portant les séquences d'instructions du produit-programme
informatique de la revendication 13.